Rationalising the denominator with radicals

hemmed

New member
Joined
Dec 26, 2016
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14
Hi there,

I'd just like to check if my logic for rationalising this denominator containing a radical is correct. I have the following to solve:

\(\displaystyle \large{\frac{x}{\sqrt[4]{x}\,}}\)

Which I have then solved as follows (and this is listed as the correct answer in my book):
\(\displaystyle \large{\frac{x}{\sqrt[4]{x}}\,\cdot\, \frac{\sqrt[4]{x^3}}{\sqrt[4]{x^3}}\,=\frac{x\sqrt[4]{x^3}}{\sqrt[4]{x^4}}\,=\frac{x\sqrt[4]{x^3}}{x}=\sqrt[4]{x^3}}\,\)

I'd just like to check that my answer of \(\displaystyle \large{{\sqrt[4]{x^3}}\,}\) is correct as the x's in the numerator and denominator have effectively cancelled themselves out, so you are therefore left with \(\displaystyle \large{{\sqrt[4]{x^3}}\,}\) or in its full form... \(\displaystyle \large{\frac{x\sqrt[4]{x^3}}{x}\,}\)
 
Last edited:
Hi there,

I'd just like to check if my logic for rationalising this denominator containing a radical is correct. I have the following to solve:

\(\displaystyle \large{\frac{x}{\sqrt[4]{x}\,}}\)

Which I have then solved as follows (and this is listed as the correct answer in my book):
\(\displaystyle \large{\frac{x}{\sqrt[4]{x}}\,\cdot\, \frac{\sqrt[4]{x^3}}{\sqrt[4]{x^3}}\,=\frac{x\sqrt[4]{x^3}}{\sqrt[4]{x^4}}\,=\frac{x\sqrt[4]{x^3}}{x}=\sqrt[4]{x^3}}\,\)

I'd just like to check that my answer of \(\displaystyle \large{{\sqrt[4]{x^3}}\,}\) is correct as the x's in the numerator and denominator have effectively cancelled themselves out, so you are therefore left with \(\displaystyle \large{{\sqrt[4]{x^3}}\,}\) or in its full form... \(\displaystyle \large{\frac{x\sqrt[4]{x^3}}{x}\,}\)
Yes that's correct.
Another way to do it is to use exponents:
\(\displaystyle \frac{x}{x^{(1/4)}} = x* x^{({-1/4})} = x^{({1 - 1/4})} = x^{({3/4})} \)
which is what you have in radical form.
 
Last edited:
Yes that's correct.
Another way to do it is to use exponents:
\(\displaystyle \frac{x}{x^{(1/4)}} = x* x^{({-1/4})} = x^{({1 - 1/4})} = x^{({3/4})} \)
which is what you have in radical form.


Excellent - thank you!
 
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